In the era BC (Before Computers), all business processes were operated by people. The operator would learn what to do by reading the organisation's Procedures manual.

Armed with this knowledge, the first item to be processed would be obtained from the IN tray (the Trigger). Based on the content of that document, the operator commenced to perform the appropriate procedure (Business Process). An example of a trigger is a Purchase Requisition. The Business process is to initiate a Purchase Order from that requisition.

Where specific information is required by the procedure, the operator would go to the "files" and "look it up" (e.g. the price of a stock item).

During the procedure, it may be necessary to record results obtained such as an updated Stock On Order situation. This is done by locating the stock ledger card in the "files", adding the details of the order just raised and returning the ledger card to the "files".

The completed Purchase Order is placed in the OUT tray for dispatch to the Supplier. The order number is recorded on the Purchase Requisition , it is stamped "ACTIONED" and added to the respective section of the "files".

A very similar thing happens when a process is performed by a computer instead of by a person: The computer becomes the "operator". The computer is instructed on the procedures and rules to be followed by reading an Application Program in place of the Procedures Manual.

The IN tray is some form of data entry device where the process is initiated (triggered) and the information required by it supplied by being keyed manually.

The "files" are held on electronic storage devices (e.g. hard disks). The information collectively is called the Business Database. The OUT tray might be a printer or a report displayed on a screen.

We are now entering an era where a new generation of thinking is being applied to performing business processes using computers.

Instead of receiving Purchase Orders on paper, produced by a customer’s computer, these orders can be received in electronic form over a network such as the Internet. Where this happens, there is no longer any need for an operator to key the order data into the Sales process, so the cost of keying that data and the cost of detecting and correcting any transcription error is avoided.

Thus, this "new generation" of business process in one business system can be triggered by the arrival of a "data stream" produced by a business process within a totally independent business system containing the attributes of the transaction requested.

Thus a business process in each of the autonomous business systems Interoperate. This is both Direct (no intervening processes) and automatic (no human intervention involved).

With Direct Interoperation, the IN and OUT trays are replaced by the network and the human operators now respond to "exceptions" and "error" conditions electronically mailed to them by the business system.

Thus, with the advent of Direct Interoperation of business processes, the promise of computer sales people over the past decades might happen at last and people freed from the drudgery of paper shuffling.

An organisation moulds its business processes to best suit its own operation, management and control requirements.

The factors which determine the procedures, rules and constraints in an organisations business processes are largely dependent on the skill, experience and competence of its people and the market and business environment within which it operates. It is often these very differences which enable an organisation to develop a competitive edge.

The level of functionality, procedures, rules and constraints incorporated into a business process can vary enormously between different organisation for the same business process. For example, an organisation which operates wholly within a single country is unlikely to have procedures covering multi-currency activity within its business processes whereas one that operates internationally could not operate without it.

Thus it will never be possible to "standardise" business processes, an ideal long expounded as necessary and striven for religeously by all the established "standards" bodies involved with interoperation. Any business organisation which adopts "standard" business processes (assuming such a thing is practical), forfeits one very effective method of achieving a competitive edge.